Lock for electrical connecters



Nov. 29, 1927. 1,651,283

R. F. LAN DRUM LOCK FOR- ELECTRICAL CONNECTERS Filed May 10, 1924WITNESSES IN VEN TOR ATTORNEYS meme! N e a i V iv '1- REGINALD rmm'meLmnnmr, or nonronk, vmemm', as srenonlo r crimes w. CAMPBELB,ornonronmvmemu. f

LOCK .ron minc'rnrcan-conimcrnns I Application and layT10,1924.;8eria1l1o. 712,441.

This invention relates inugeneral to looks ed base or plug 15" adaptedto be threaded 85 for electrical connecters,.and is particularly intothe shell 11 of thefsocket10. designed for locking an electric lamp 'toits I M n i id d. f 1 ki g-th' l g 15' p v socket, although of course aswell adapted in the socket so-as to 'prevent.accidental or v 5 for use1n locking sim lar fittings; unauthorized removalof the electric lightbr' I ,The object of the invention is to-provide a lamp 14. This. meansincludes a locking device of this character which is effective to strip16 inserted between; the shell 11 and the prevent the unauthorized :oraccidental reinsulation 13 f th casin 112 The inn moval of electriclamps from their sockets or end of the strip 16 is bent nwardly atright" fittings and which is also of simple and (1 angles to provide anattaching portion 18 rable construction, reliable and effective which,extends througha slotfor opening 05 operation and easyand comparativelyinexformed inthe shell 11 and is secured to the penslve to manufactureand apply. porcelain structure of the socket 10 in any A further objectis to provide a device of, suitabl manner as by means of a screw 19.-

1 this character and having 'the foregoing In this manner the lockingstrip 16 is firmly enumerated advantages and capacities and and rigidlyheld in position except that ltSl -which' may be readily released topermit outer e d ma b flexed to some extent to authorized removal of thelamp from its provide for the releasing action to be later socket onfitting. described, .At the outer end of the locking 20' Other objectsand advantages reside in strip 16 an inwardly extending locking lugcertain novel features of the construction, 20 is rovided; This lug 20is formed with arrangement and combination of parts which an in' lii'i dor beveled surface 21 and with will be'hereinafter more fully describednd sharp,point 22. The beveled surface 21 particularly pointed out inthe. appen ed p rmits the 111 15 of the lamp to be so 25 claims,reference being had tothe accom-. turned 'as to introduce the lamp intothe' r y g drawings f g a P Of this socket 10, but the point 22 preventsunauspecification, and in which: J thorized or accidental removal of theplug Figure 1 is a view in perspective showing 15 trom the socket '10 sice this point 22 5111 916613156 light SOCkBt equ pped W the bites intothe material of t eplug when the present invention, the electric lampbemg le a d lug are tu ned to e v the shown prior to assembly, lamp fromthe socket. The lug 20 is located g e 2 i a w p y i elevation and at theouter endof the shell 11 but the caspartly in section illustrating theinvention i g 12 d i l ti n 13 ov l th lug to I with the lamp partlyintroduced into its n l it, 35 socket, When it is desired to remove thelamp or Figure 3 is av-iew in perspective showlng bulb from the socket areleasing too 25 the manner of releasing the lock, the cashown in Figure3 must be employed, and ing of the socket being shown in dotted linesincludes a tapered and twisted shank 26 and i and partially omitted. forthe sake of illusan insulated handle member 27. The outer tration, andend of the twisted shank of the releasing Figure 4 is a perspective viewshowing tool is introduced between the lug 20, the the inventionembodied in a different type strip 16 and the shell 11 and tool is thenof fitting or connecter. turned so as to pry or flex the lug 20 awayReferring to the drawings, and more arfrom the plug 15 to permit theplug to be ticularly to Figures 1 to 3 inclusive, the removed from thesocket. The twist of the numeral 10 designates an electric lamp shank 26permits theitool to pry the lug 20 socket which may be of anyconventional away from the plug withoutthe shank'be- 7 type orconstruction. As usual the socket coming bound in the structure ofthesocket. includes a threaded contact shell 11 which The locking strip16 and the locklng In is enclosed in a casing 12, a lining 13 of in- 20are constructed oftoolf steel and with suc sulation being providedbetween the casing a construction the point or blt 22 of the lock- 1 12-and the shell 11. ing lug will cut o the plug 15 of the elec An electriclamp designated at 14 is protric lamp before permittmg removal of the Ivided, and, as usual has an externally thread lamp from its socket. .Theshank of the releasing tool is also constructed of tool steel to providenecessary torsional strength.

\Vith this arrangement a simple, practical and comparatively inexpensivelock is had which is effective to prevent unauthorized or accidentalremoval of the lamp from its socket, and which etl'ectively preventstheft of electric light bulbs. These advantages are had without alteringor impairing in any way the structure or capacity of the lamp or socketto carry out its usual and customary functions.

The arrangement shown in Figure 4 is identical with that shown inFigures 1 to 3 except that the locking strips and its lug are organizedwith a different type of fitting, which is designated at 30. Thisfitting 3G includes a porcelain body 3'] and a threaded shell 32 fittedin the porcelain body. The locking strip 16 has an attaching portion 18as before, and this attaching portion is apertured to receive a screw 33forming a part of the structure of the fitting 30. A nut 34 is threadedon the screw 33 and engages the attaching portion 18 to hold the lockingstrip in position.

It is to be understood that the present in'- venion is adapted for usewith any standard or known fitting or connecter, and that various meansmay be provided for securing the locking strip in position.

I claim 1. A look for securing a screw-threaded plug in a socket of anelectrical connection and con'iprising a locking strip extendinglengthwise of the socket, connected thereto and concealed in thestructure thereof, and a locking lug integral with the strip, said lugextending in a plane at right angles to the longitudinal axis of thesocket and having a beveled edge permitting the plug to be threaded intothe socket and also having a point, the mounting of the strippositioning the point so as to cause it to bite into the material of theplug to prevent removal of the plug from the socket;

'2. A lock for securing a screw-threaded plug in a socket of anelectrical connection and comprising a lock strip extending lengthwiseot the socket and concealed in the structure thereof, means forfastening the inner end of the strip to the socket, and a locking lugintegral with'the outer end of the strip and located just inwardly ofthe" outer end of the socket, said lug extending in a plane at rightangles to the longitudinal axis of the socket and having a beveled edgepermitting the plug to be threaded into the socket and also having apoint, the strip being positioned and niountexgl to cause the point tobite into the material of the plug to prevent unauthorized removal ofthe plug from the socket. the portion of the strip adjacent the lugadapted to'be'pried outwardly by a suitable tool to disengage the pointfrom the plug.

REGINALD FLEMING LANDRUM.

